Fuel containment

ABSTRACT

An aircraft having an internal liquid fuel tank mounted in a wing thereof, with a wall of the tank facing a jet engine mounted on the wing, is provided with means for containing fuel leaking through a puncture in that wall of the tank caused by a broken compressor blade or other part flung out of the rotary portion of the engine. A containment chamber is formed by an outer wall spaced from the vulnerable wall of the tank, and an inflatable bag is mounted in the chamber in a deflated condition for storage. The deflated bag is rolled around a drum and its outer edge is permanently secured along the lower edge of the outer wall. A leak detector in the chamber senses a fuel leak and responds thereto by automatically triggering a control valve to release pressurized gas into the gas bag to inflate it. As the bag inflates, the drum is rolled across the inner face of the outer wall and is retained by locking means so that the erected bag extends across and overlies any puncture in the area of the outer wall covered by the bag, such as may have been caused by a flying blade.

United States Patent 1 Farmer June 5, 1973 [54] FUEL CONTAINMENT Primar Examiner-Milton Buchler I l, y [75] Inventor z sg C lfford Farmer Blflsto Assistant ExaminerGregory W. OConnor g Attorney-Cushman, Darby & Cushman [73] Assignee: British Aircraft Corporation Limited, London, England [57] ABSTRACT [22] Filed: Nov. 5, 1970 An aircraft having an internal liquid fuel tank mounted in a wing thereof, with a wall of the tank fac- [211 Appl' 87279 ing a jet engine mounted on the wing, is provided with means for containing fuel leaking through a puncture [52] US. Cl. ..244/135 B i hat wall f the tank caused by a broken compres- [51] Int. Cl. ..B64d 37/32 sor blade r h r p r flung out of the rotary portion [58] Field of Search ..244 135 R, 135 B, of the g A Containment chamber is formed y 244/1 19, 121; 220/63 A; 114/69, 228, 54 outer wall spaced from the vulnerable wall of the tank, and an inflatable bag is mounted in the chamber in a [56] References Cited deflated condition for storage. The deflated bag is r rolled around a drum and its outer edge is per- UNITED STATES PATENTS manently secured along the lower edge of the outer 2 757 362 7/1956 G tk w H 244/135 5 wall. A leak detector in the chamber senses a fuel leak 7/1896 s s s 114/22'8 and responds thereto by automatically triggering a 2 857 078 10/1958 Wolfertllllillilll... 1 i 4/54 ux control valve to release Pressurized gas the gas 2,743,510 5/1956 Mauney et al. ..244 135 B bag to "mate 1,529,064 3/1925 Hammond ..220/63 A AS the g inflates the drum i rolled across h inner 7/ gl 4 1 face of the outer wall and is retained by locking means 2924l92 24 i g; 4 so that the erected bag extends across and overlies any g puncture in the area of the outer wall covered by the FOREIGN PATENTS OR APPLICATIQNS bag, such as may have been caused by a flying blade.

1,283,347 12/1961 France ..114/228 14 Claims, 8 Drawing Figures ZR A or 19 i\ i t PATENTEUJUH 5 1973 SHEET Q (If 6 INVENTOR v a TORNEYfi BY W D'Z IZT PATENTEDJUN 51m 3.737,125

SHEET 5 BF 6 INVENTOR M 7 G. 6%. R INVENTOR v '1' WWW ATTORNEYS FUEL CONTAINMENT This invention relates to a sealing apparatus for the containment of fluid leaks following rupture of the wall of the tank. It is particularly but not exclusively applicable to aircraft fuel tanks.

If an aircraft gas turbine engine suffers a compressor or turbine disc failure, it is possible for a fragment of the disc to pass out of the engine casing and enter an adjacent fuel tank. It is often necessary for a fuel tank to be situated close to the engine, in which case a fire risk may be caused should fuel from a punctured tank flow onto the hot engine. To protect all vulnerable portions of the tank with armor plating is not desirable because of weight considerations.

According to the present invention apparatus for the containment of fluid leaks from a rupture wall of a tank comprises, an outer wall member spaced from the wall of the tank so as to define a chamber therebetween, an inflatable gas bag stored within the chamber, and means to inflate the gas bag so as to erect it and cause it to extend to cover the inside face of the outer wall member and overlie any puncture therein.

Preferably the inflatable gas bag is permanently secured along one edge of the chamber, and locking means is provided to retain the free end of the inflatable member in position along the opposite edge of the chamber, when it has been inflated. The gas bag may be wound on a roller for storage when in a deflated condition, unrolling from the roller during inflation.

The invention may be put into practice in various ways, but one specific embodiment and a modification thereof will now be described by way of example and with reference to the accompanying drawings, in which:

FIG. 1 is a half front elevation of an aircraft,

FIG. 2 is a sectional front elevation of part of an aircraft wing showing one of the inflatable gas bags in its stored position therein,

FIG. 3 is a view similar to FIG. 2 showing the inflatable gas bag in its operational position and the side wall of the wingtank ruptured, and

FIG. 4 is a transverse section through the aircraft wing showing two of the inflatable gas bags in their operational position,

FIG. 5 is a isometric section of the wing showing one of the inflatable gas bags in its operational position, certain parts of the structure have been omitted for clarity,

FIG. 6 is a plan view of one of the inflatable gas bags being initially wound around a drum,

FIG. 7 is a cross-section on a line VI VI of FIG. 6,

FIG. 8 is a sectional plan ofa wing compartment containing a modified construction of inflatable member formed with a number of separate compartments.

In the embodiment of FIGS. 1 to 7, an aircraft wing 10 contains within its structure an internal liquid fuel tank 11. Precautions must be taken to protect the fuel tank 11 from being ruptured in the event ofa compressor disc failure in an adjacent gas turbine engine 12, and to reduce fire risk in the event of such a rupture.

The bottom surface of the fuel tank 11 is protected by a layer of armor plating l3 situated at positions adjacent to the compressor stages of the engine 12. One side of the fuel tank 11 is defined by a side wall 14 which has no armor protection against being ruptured. A pair of inflatable gas bags 15 are mounted side by side and spaced from the side wall 14 and can be erected by inflation to stand up against a honeycombsandwieh outer wall member 16 to contain a fuel leak in the event of the side wall 14 becoming ruptured. Each gas bag 15 is made of a known synethetic rubber material, such as that known by the trade name NEO- PRENE and manufactured by E.I. du Pont de Nemours and C0.Inc. the wall-to-wall thickness of the inflated gas bag 15 being controlled by reinforced strands of material 29 joined to the two inside wall surfaces and extending between them. Each gas bag 15 is permanently secured along its bottom edge to the bottom wall of a chamber 18 between the tank side wall 14 and the honeycomb-sandwich outer wall 16, and is wound around a drum 17 when deflated. The gas bag 15 is protected in its stored position by a right-angled armor plate member 19 which extends the length of the fuel tank 11. The gas bag 15 is automatically inflated when a triggering device 20 such as thermistor senses a fuel leak and in response thereto triggers a control valve 21 and allows a supply of nitrogen from a bottle 22 (FIG.

5) to pass through pipes 23, 23A and into the gas bag 15, causing the drum 17 to roll upwards over the inside face of the honeycomb-sandwich wall 16 as the gas bag 15 is unrolled and erected. The drum 17 is guided throughout its upward travel by a set of guide blocks 24 and 25. When the drum reaches the top of the chamber 18, a set of spring-loaded retaining clips 26 and 27 secures the drum 17 in contact with a foam member 28 at the top of the chamber 18, to latch the inflated gas bag 15 in its fully-erected deployed position.

If a compressor disc failure takes place, a fragment 31 may pass through the honeycomb-sandwich wall 16 and the tank side wall 14 causing a rupture 30 (FIG. 3) through which fuel will flow. The triggering device'20 immediately senses the fuel leak and allows the nitrogen supply to be fed along the pipes 23 and 23A and into the inflatable gas bags 15 to inflate the latter, one of which immediately begin to deploy over the hole 30 in the honeycomb-sandwich wall 16. Once the inflatable gas bag is in its fully-deployed erect position, it will prevent fuel from leaking out of the chamber 16 onto the engine 12, hence the risk of fire is reduced.

As shown in FIG. 4, there are several inflatable gas bags 15 disposed side by side along the length of the side wall 14 of the fuel tank. To ensure a good seal between laterally-adjacent inflatable gas bags when erected the side edge portions 32 of each gas bag are folded over when they are initially wound around the drums 17 (see FIG. 7), so that on inflation they will be able to spring out and butt together and against the end walls of the chamber to form a leak proof seal.

In an alternative construction, (see FIG. 8) a single inflatable gas bag 33 is mounted in each wing 10 between the side wall 14 of the fuel tank and the honeycomb outer wall 16 and is constructed with a number of separate internal compartments 34, each with its own nitrogen gas supply pipe 23A, so that the inflatable gas bag 33 will still be erected and deployed effectively even if one or more of its compartments 34 should suffer damage while it is still stored around the drum 17 or in the deployed condition.

What we claim as our invention and desire to secure by Letters Patent is:

1. Apparatus for the containment of fluid leaks from a ruptured wall of a tank, which comprises a tank having a wall liable to accidental damage, an outer wall having an internal face spaced from the said wall of the tank and defining therewith a chamber therebetween, an inflatable gas bag stored within the chamber in a deflated and collapsed condition, and means for inflating the gas bag to erect it, the erected gas bag when so inflated extending over and covering an area of the internal face of the outer wall member to overlie any puncture therein; the inflatable gas bag having a marginal portion permanently secured in the chamber along one edge of the said outer wall, locking means in the chamber for retaining a portion of the gas bag which is remote from said permanently-secured marginal portion when inflated, said locking means holding said retained remote portion of the inflated gas bag in position along the opposite edge of the outer wall of the chamber; a roller around which the inflatable gas bag is rolled for storage when deflated and collapsed, and from which the gas bag becomes unrolled during inflation; the outermost portion of the deflated gas bag when rolled on the roller being the said permanently-secured marginal portion, the roller, during inflation being rolled across the internal face of the outer wall towards the opposite edge thereof by the erection of the gas bag whilst the latter unrolls itself from the roller; the said locking means comprising a set ofspring-loaded retaining clips arranged to engage and lock the roller in its position adjacent to the said opposite edge of the outer wall.

2. Apparatus as claimed in claim 1 which includes a supply of pressurized gas connected to the inflatable gas bag via a control valve, and fluid leak detector means in the chamber operatively associated with the control valve, the leak detector means being constructed and arranged to sense a leakage of fluid from the tank into the chamber and in response thereto to actuate the control valve automatically to admit pressurized gas from the supply into the gas bag to inflate the latter.

3. Apparatus as claimed in claim 1 in which the inflatable gas bag is formed with at least two separate compartments each having its own gas supply inlet for inflation.

4. Apparatus as claimed in claim 1 in which opposite side walls of the or each inflatable gas bag are mechanically interconnected by non-extensible reinforcing filaments which limit the separation of the walls of the bag on inflation.

5. Apparatus for the containment of fluid leaks from a ruptured wall of a tank, which comprises a tank having a wall liable to accidental damage, an outer wall having an internal face spaced from the said wall of the tank and defining therewith a chamber therebetween, a plurality of inflatable gas bags each stored within the chamber in a deflated and collapsed condition, and means for inflating each gas bag to erect it, each erected gas bag when so inflated extending over and covering an area of the internal face of the outer wall member to overlie any puncture therein; said inflatable gas bags being mounted side by side in the chamber along the outer wall thereof, lateral portions of respec tive inflatable gas bags are folded when the respective bag is wound around the roller so that on inflation each lateral portion will unfold and butt against the lateral portion of an adjacent gas bag or against an end wall of the chamber.

6. An aircraft including a wing, a liquid fuel tank mounted within the interior of the wing, the tank having a wall liable to accidental damage, and apparatus for the containment of fuel leaks from the said wall, which apparatus comprises an outer wall having an internal face spaced from the said wall of the tank and defining therewith a chamber therebetween, an inflatable gas bag stored within the chamber in a deflated and collapsed condition, and means for inflating the gas bag to erect it, the erected gas bag when so inflated extending over and covering an area of the internal face of the outer wall member to overlie any puncture therein.

7. An aircraft as claimed in claim 6, in which the inflatable gas bag has a marginal portion permanently secured in the chamber along one edge of the said outer wall, and which includes locking means in the chamber for retaining a portion of the gas bag which is remote from said permanently-secured marginal portion when inflated, said locking means holding said retained remote portion of the inflated gas bag in position along the opposite edge of the outer wall of the chamber.

8. An aircraft as claimed in claim 6, including a roller around which the inflatable gas bag is rolled for storage when deflated and collapsed, and from which the gas bag becomes unrolled .during inflation.

9. An aircraft as claimed in claim 8, wherein the out ermost portion of the deflated gas bag when rolled on the roller is the said permanently-secured marginal portion, and in which during inflation the roller 15 is rolled across the internal face of the outer wall towards the opposite edge thereof by the erection of the gas bag whilst the latter unrolls itself from the roller.

10. An aircraft as claimed in claim 9, in which the said locking means comprises a set of spring-loaded retaining clips arranged to engage and lock the roller in its position adjacent to the said opposite edge of the outer wall.

11. An aircraft as claimed in claim 6, which includes a supply of pressurized gas connected to the inflatable gas bag via a control valve, and fluid leak detector means in the chamber operatively associated with the control valve, the leak detector means being constructed and arranged to sense a leakage of fluid from the tank into the chamber and in response thereto to actuate the control valve automatically to admit pressurized gas from the supply into the gas bag to inflate the latter.

12. An aircraft as claimed in claim 6, which includes several said inflatable gas bags mounted side by side in the chamber along the outer wall thereof, and in which lateral portions of an inflatable gas bag are folded when the bag is wound around the roller so that on inflation each lateral portion will unfold and butt against the lateral portion of an adjacent gas bag or against an end wall of the chamber.

13,. An aircraft as claimed in claim 6 in which the inflatable gas bag is formed with at least two separate compartments each having its own gas supply inlet for inflation.

14. An aircraft as claimed in claim 6 in which opposite side walls of the or each inflatable gas bag are mechanically interconnected by non-extensible reinforcing filaments which limit the separation of the walls of the bag on inflation.

* a :r a: 

1. Apparatus for the containment of fluid leaks from a ruptured wall of a tank, which comprises a tank having a wall liable to accidental damage, an outer wall having an internal face spaced from the said wall of the tank and defining therewith a chamber therebetween, an inflatable gas bag stored within the chamber in a deflated and collapsed condition, and means for inflating the gas bag to erect it, the erected gas bag when so inflated extending over and covering an area of the internal face of the outer wall member to overlie any puncture therein; the inflatable gas bag having a marginal portion permanently secured in the chamber along one edge of the said outer wall, locking means in the chamber for retaining a portion of the gas bag which is remote from said permanently-secured marginal portion when inflated, said locking means holding said retained remote portion of the inflated gas bag in position along the opposite edge of the outer wall of the chamber; a roller around which the inflatable gas bag is rolled for storage when deflated and collapsed, and from which the gas bag becomes unrolled during inflation; the outermost portion of the deflated gas bag when rolled on the roller being the said permanently-secured marginal portion, the roller, during inflation being rolled across the internal face of the outer wall towards the opposite edge thereof by the erection of the gas bag whilst the latter unrolls itself from the roller; the said locking means comprising a set of spring-loaded retaining clips arranged to engage and lock the roller in its position adjacent to the said opposite edge of the outer wall.
 2. Apparatus as claimed in claim 1 which includes a supply of pressurized gas connected to the inflatable gas bag via a control valve, and fluid leak detector means in the chamber operatively associated with the control valve, the leak detector means being constructed and arranged to sense a leakage of fluid from the tank into the chamber and in response thereto to actuate the control valve automatically to admit pressurized gas from the supply into the gas bag to inflate the latter.
 3. Apparatus as claimed in claim 1 in which the inflatable gas bag is formed with at least two separate compartments each having its own gas supply inlet for inflation.
 4. Apparatus as claimed in claim 1 in which opposite side walls of the or each inflatable gas bag are mechanically interconnected by non-extensible reinforcing filaments which limit the separation of the walls of the bag on inflation.
 5. Apparatus for the containment of fluid leaks from a ruptured wall of a tank, which comprises a tank having a wall liable to accidental damage, an outer wall having an internal face spaced from the said wall of the tank and defining therewith a chamber therebetween, a plurality of inflatable gas bags each stored within the chamber in a deflated and collapsed condition, and means for inflating each gas bag to erect it, each erected gas bag when so inflated extending over and covering an area of the internal face of the outer wall member to overlie any puncture therein; said inflatable gas bags being mounted side by side in the chamber along the outer wall thereof, lateral portions of respective inflatable gas bags are folded when the respective bag is wound around the roller so that on inflation each lateral portion will unfold and butt against the lateral portion of an adjacent gas bag or against an end walL of the chamber.
 6. An aircraft including a wing, a liquid fuel tank mounted within the interior of the wing, the tank having a wall liable to accidental damage, and apparatus for the containment of fuel leaks from the said wall, which apparatus comprises an outer wall having an internal face spaced from the said wall of the tank and defining therewith a chamber therebetween, an inflatable gas bag stored within the chamber in a deflated and collapsed condition, and means for inflating the gas bag to erect it, the erected gas bag when so inflated extending over and covering an area of the internal face of the outer wall member to overlie any puncture therein.
 7. An aircraft as claimed in claim 6, in which the inflatable gas bag has a marginal portion permanently secured in the chamber along one edge of the said outer wall, and which includes locking means in the chamber for retaining a portion of the gas bag which is remote from said permanently-secured marginal portion when inflated, said locking means holding said retained remote portion of the inflated gas bag in position along the opposite edge of the outer wall of the chamber.
 8. An aircraft as claimed in claim 6, including a roller around which the inflatable gas bag is rolled for storage when deflated and collapsed, and from which the gas bag becomes unrolled during inflation.
 9. An aircraft as claimed in claim 8, wherein the outermost portion of the deflated gas bag when rolled on the roller is the said permanently-secured marginal portion, and in which during inflation the roller 15 is rolled across the internal face of the outer wall towards the opposite edge thereof by the erection of the gas bag whilst the latter unrolls itself from the roller.
 10. An aircraft as claimed in claim 9, in which the said locking means comprises a set of spring-loaded retaining clips arranged to engage and lock the roller in its position adjacent to the said opposite edge of the outer wall.
 11. An aircraft as claimed in claim 6, which includes a supply of pressurized gas connected to the inflatable gas bag via a control valve, and fluid leak detector means in the chamber operatively associated with the control valve, the leak detector means being constructed and arranged to sense a leakage of fluid from the tank into the chamber and in response thereto to actuate the control valve automatically to admit pressurized gas from the supply into the gas bag to inflate the latter.
 12. An aircraft as claimed in claim 6, which includes several said inflatable gas bags mounted side by side in the chamber along the outer wall thereof, and in which lateral portions of an inflatable gas bag are folded when the bag is wound around the roller so that on inflation each lateral portion will unfold and butt against the lateral portion of an adjacent gas bag or against an end wall of the chamber.
 13. An aircraft as claimed in claim 6 in which the inflatable gas bag is formed with at least two separate compartments each having its own gas supply inlet for inflation.
 14. An aircraft as claimed in claim 6 in which opposite side walls of the or each inflatable gas bag are mechanically interconnected by non-extensible reinforcing filaments which limit the separation of the walls of the bag on inflation. 